pgsql: Doc: Improve wording of multiple places in documentation

Doc: Improve wording of multiple places in documentation

This has been found during its translation.

Author: Liudmila Mantrova
Discussion: https://postgr.es/m/CAEkD-mDJHV3bhgezu3MUafJLoAKsOOT86+wHukKU8_NeiJYhLQ@mail.gmail.com
Backpatch-through: 12

Branch
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REL_12_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/b298e37013683f896b0a224eee50937730faeca8

Modified Files
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doc/src/sgml/catalogs.sgml         | 20 ++++++-------
doc/src/sgml/client-auth.sgml      |  9 +++---
doc/src/sgml/config.sgml           | 29 +++++++++---------
doc/src/sgml/ecpg.sgml             | 60 ++++++++++++++++++++------------------
doc/src/sgml/libpq.sgml            | 14 ++++-----
doc/src/sgml/maintenance.sgml      |  2 +-
doc/src/sgml/planstats.sgml        |  4 +--
doc/src/sgml/ref/create_table.sgml |  6 ++--
doc/src/sgml/storage.sgml          |  3 +-
9 files changed, 77 insertions(+), 70 deletions(-)